Question

The process of fusion of male gamete and female gamete is called
(a) Pollination
(b) Fertilisation
(c) Cell maturation
(d) Cell elongation

Answer 1

Hint: The process is also known as syngamy. Fertilization in humans is the fusion of a human egg (ovum) and sperm. This usually occurs in the ampulla region of the fallopian tube. This process eventually results in the formation of a zygote cell. The cell undergoes rapid division to form an embryo that eventually becomes a fetus after two weeks.

Complete answer:
In sexual reproduction, a haploid sperm cell from the male parent fertilizes with the haploid egg cell from the female parent to produce a diploid zygote. These cells contain half of the number of chromosomes as the parent and are therefore haploid.
There are three stages to fertilization which ensure that the appropriate egg and sperm fertilize and to check that only one sperm enters the egg:
- Chemotaxis: This basically includes guiding sperm to move towards a concentration gradient of a particular chemical that is secreted from the oocyte and helps in reaching the oocyte.
- Acrosomal reaction or sperm activation: Acrosome is generally a modified lysosome that has zona digesting enzymes. The acrosome reaction with the zona pellucida of the ovum provides the sperm with an enzymatic drill to penetrate into the zona pellucida layer.
- Adhesion: After the penetration in zona pellucida, the sperm adheres to and fuses with the plasma membrane of the oocyte.

Additional information: Sperm are motile and have a flagellum on the other hand female gamete(ovum) is nonmotile and relatively large in comparison with the male gamete. This condition is termed as ‘anisogamy’ or ‘heterogamy’, wherein the female and male gametes are of two different sizes.
Pollination which is known to be a process of transfer of pollen grains from the anther to the stigma of a flower. It is necessary for reproduction and helps in the production of seeds.
Cell maturation is a stage when plant cells lose their ability to grow; it is a developmental process, independent of morphogenetic change, that is required for a cell to attain its fully functional state.
Cell elongation is a form of developmental process that is regulated by sunlight and phytohormones and is important for plant growth
So, the correct answer is ‘(b) Fertilisation’.

Note: External fertilization is a mode of reproduction in which sperm from a male organism fertilizes with an egg cell outside of the female's body whereas, in internal fertilization, sperms are introduced through insemination and then combined with an egg inside the body of a female organism.